！<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=, initial-scale=1.0">
    <title>Document</title>
</head>
<style>


    .box
     {width:200px;
    height:200px;
    padding: 20px 0;
    border: 5px solid skyblue;
     }
    .demo{width:100px;
    height:100px;
    background-color: rgb(141, 119, 123);
    margin: 0 auto;

    }
    
     
     </style>
    


<body>
    
    <div class="box"> 
     <div class="demo"></div>
   
    </div>

</body>
</html>